Japanese patent application publications No. 2007-54808A and No. 2006-68711A disclose conventional electrostatically atomizing devices. The conventional electrostatically atomizing device is provided for generating a mist of the charged minute water particles of nanometer sizes. The electrostatically atomizing device comprises an emitter electrode, a cooling means, and a high voltage source. The emitter electrode comprises a rod and a discharge head. The rod has one end holding the discharge head and has the other end thermally coupled to the cooling means. The cooling means is configured to cool the discharge head through the rod in order to condense vapor in air around the discharge head into water. Consequently, the water is condensed on the discharge head. The cooling means condenses the vapor in the air into a sufficient amount of the water onto the discharge head immediately after the cooling means is started. A sufficient amount of water supplied onto the discharge head is also a suitable amount of the water for generating the mist of the charged minute water particles by the electrostatically atomization. The high voltage source is configured to apply a high voltage to the emitter electrode in order to electrostatically atomize the water held by the discharge head.
When the cooling means cools the emitter electrode, the water is condensed on a surface of the discharge head. Subsequently, the high voltage source applies the high voltage to the discharge head through the rod, thereby the electrical field being generated between the emitter electrode and ground (earth). The electrical field moves the water on the surface of the discharge head to the tip of the discharge head. Then, the water at the tip of the discharge head is electrically charged by the electrical field. The electrically charged water receives a Coulomb force from electrical field generated between the emitter electrode and ground (earth). As a result, the electrically charged water is pulled along the direction of the electrical field, thereby the Taylor cone being formed at the water on the discharge head. And then, the Taylor cone keeps receiving the Coulomb force, Rayleigh Breakups are caused at the tip of the Taylor cone. According to the Rayleigh Breakups, the mist of the charged minute water particles of nanometer sizes is generated from the tip of the Taylor cone. In this way, the electrostatically atomizing device continuously generates the mist of the charged minute water particles of nanometer sizes without being supplied with the water by users. Therefore, the electrostatically atomizing device with above configurations has high usability.
However, because the cooling means cools the discharge head through the rod, the cooled rod also condenses the vapor in the air surrounding the rod into water on a surface of the rod. The water on the surface of the rod is moved by the electrical field toward the discharge head. Therefore, the discharge head is also supplied with the water from the rod. That is, the discharge head is supplied with excessive amount of the water. In the case where the excessive amount of the water is supplied to the discharge head, the Taylor cone having a shape which is suitable for electrostatically atomizing is not formed.